<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Document</title>
  <style type="text/css">
    .root {
      background-color: orange;
    }
    .second {
      background-color: lightgreen;
    }
    .third {
      background-color: lightblue;
    }
  </style>
</head>
<body>
  <div id="app" class="root">
    <div>{{root}}</div>
    <second-com></second-com>
    <second-com></second-com>
  </div>
  <script type="text/javascript" src="js/vue.js"></script>
  <script type="text/javascript">
    /*
      Vue调试工具安装与基本使用
    */
    Vue.component('second-com',{
      data: function(){
        return {
          second: '二级组件'
        }
      },
      template: `<div class='second'>
        <div>{{second}}</div>
        <third-com></third-com>
        <third-com></third-com>
        <third-com></third-com>
      </div>`
    });
    Vue.component('third-com',{
      data: function(){
        return {
          third: '三级组件'
        }
      },
      template: '<div class="third"><div>{{third}}</div></div>'
    });
    
    var vm = new Vue({
      el: '#app',
      data: {
        root: '顶层组件'
      }
    });
  </script>
</body>
</html>
